Control device for radio receiving sets



2 Sheets-Sheet 1 R. w. MOHR CONTROL DEVICE FOR RADIO RECEIVING SETS Filed bee. 10, 1935 June 11, 1940.

Invehtnr Rug EPWJVIUHP Fittmrnegs BRQHUCHET N L/M w 2 Sheets-Sheet 2 R. W. MOHR CONTROL DEVICE FUR RADIO RECEIVING SETS Filed Dec. 10, 1958 June 11,

Invrzntmr Roger" W. MEHIT H Z H'UIEITTIEHE Patented June 11, 1940 V UNITED STATES PATENT OFFICE Roger W. Mohr, Burlington, Wis.

Application December 10, 1938, Serial No. 244,879

4 Claims.

This invention appertains to radio, and more particularly to a novel control device for radio receiving sets.

It is now customary to employ a so-called "doublet aerial with modern radio receiving sets. This aerial consists of divided antenna wires, with the adjacent ends of the wires insulated from one another. For the best reception, a single antenna wire is used for the local wave band, and for short wave reception, best results are had by using both sections of the doublet antenna. The radio receiving sets are equipped with binding posts for connection with both sections of the antenna wires and a binding post for the ground wire. Likewise, best results are had for the local or national wave band. where the set is provided with a ground connection.

It is, therefore one of the primary objects of my invention to provide novel means, which can be conveniently located adjacent theradio receiving set for permitting the instant connection of one straight antenna section with the receiving set, or both antenna sections with the radio receiving set.

Another salient object of my invention is to provide a novel appliance which will not only permit the instant selective connection of one or both sections of a doublet aerial with a radio receiving set, but will also permit the entire disconnection of the receiving set from the aerial and the grounding of both sections of the aerial, whereby to effectively guard the receiving set against lightning.

A still further object of my invention is to provide means for automatically permitting the grounding of the receiving set when a single straight aerial section is used, and for disconnecting the ground connection when both sections of the doublet aerial are used.

With these and other objects in view, the invention consists in the novel construction, arrangement, and formation of parts, as will be hereinafter more specifically described, claimed, and illustrated in the accompanying drawings, in which drawings:

Figure 1 is a perspective view of my improved control device per se, looking from the inside thereof.

Figure 2 is a perspective view of the control device per se, looking from the outside thereof, the view also showing diagrammatically the means for connecting the control device with a doublet aerial and with a radio receiving set.

Figure 3 is a detail, fragmentary sectional view through the device, taken on the line 3-3 of Figure 1, looking in the direction of the arrows, illustrating the ground clips.

Figure 4 is a fragmentary detail sectional view taken on the line 44 of Figure 1, looking in the direction of the arrows, illustrating the clips for 5 connection with the antenna wires leading to the radio receiving set.

Figure 5 is a vertical sectional view through a modified form of my control device, taken substantially on the line 5-5 of Figure 6, lool ing in the direction of the arrows, illustrating means for permitting the grounding of the radio receiving set when a single straight aerial section is used.

Figure 6 is a horizontal sectional view taken on the line 6-43 of Figure 5, looking in the direction of the arrows.

Figure '7 is an enlarged, fragmentary, detail vertical section taken on the line 'l-l' of Figure 5, looking in the direction of the arrows, illustrating the means for pivotally connecting the ground arms to the casing.

Referring to the drawings in detail, wherein similar reference characters designate corresponding parts throughout the several views, the letter C generally indicates my improved control device, which, as shown, includes a protecting housing or casing Hi. This housing or casing I0 is preferably moulded from insulating material, but in the present instance I have shown the same stamped or otherwise formed from sheet metal.

The casing or housing I ll includes an outer wall I 1, bottom and top walls I2 and I3, and side walls I4 and 15. The walls 12, :3, M, and I5 have formed thereon right-singularly extending attaching flanges IE, and these flanges can be employed for conveniently connecting the casing to a wall or other support, which closes the casing. If preferred, a removal closure wall can be provided.

Located within the box or casing is a single switch lever ll, which includes a pair of switch blades l8 and i9. These blades are rigidly connected at their outer ends by means of 'a strip of insulation. 20. This strip of insulation can be extended laterally and shaped to form a manipulating handle 2|. This handle is extended through an arcuate slot 22 formed in the front wall ll of the box or casing ill. The inner ends 50 of the switch arms are pivotally connected, as at 23, to clips 24, and these clips are, in turn, secured to the side wall M of the casing adjacent the lower end thereof. By referring to Figure 1, it can be seen that the clips 24 are insulated 55 one from the other by a strip or a plate of insulation 25. Naturally, if the box or casing is formed from insulation this strip can be eliminated.

Rigidly secured to the bottom wall I2 is a pair of spaced ground clips 26, and these clips are rigidly secured to and insulated from the casing by insulating members 21. Both of the clips 26 are electrically connected to a ground binding post 28, and this binding post has connected thereto a ground wire 29. The clips 26 are located in the path of the switch blades I8 and I9, and, consequently, when the switch is in its lowered position, the same is in engagement with the ground clips.

The clips 24 for the blades of the switch are insulated one from the other, as heretofore set forth, and the clips have electrically connected therewith binding posts 30 and 3|. The binding post 30 for the switch blade I8 has electrically connected therewith an antenna lead-in wire 32, while the binding post 3| for the switch blade I9 has electrically connected therewith an aerial lead-in wire 33. These wires 32 and 33 are electrically connected with the sections 34 and 35 of the doublet antenna or aerial 36. The sections 34 and 35 are insulated one from the other in any appropriate manner, such as by an insulator 31.

Secured to the side wall M on the casing ||l above the switch blade clips 24 are clips 38 and 39. The clips 38 and 39 are insulated one from the other in any preferred manner, and have electrically connected therewith binding posts 40 and 4| respectively. This connection is similar to switch blade clips 24, and the binding posts 40 and 4| have electrically connected thereto wires 42 and 43. The wire 42 is electrically connected with the binding post 44 on a radio receiving set 45, while the wire 43 is electrically connected with the binding post 46 on the radio receiving set 45.

On the radio receiving set the binding posts 44 and 46 are marked respectively a for indicating a straight antenna, and D, indicating the full use of the doublet antenna. The radio receiving set is also provided with a binding post 41, which is marked G on the radio receiving set indicating ground, and this binding post 41 has electrically connected thereto a wire 48 which leads to any preferred ground, as shown in Figure 2 of the drawings. The wire 29 for the clips 26 can be connected to an outside ground or to the same ground as the terminal 41 of the radio receiving set.

Referring back to the clips 38 and 39, it will be noted that the clip 38 is of a considerably greater length than the clip 39, and, hence, when the switch lever I1 is swung to a raised position, the switch blade IE will engage the clip 38 prior to the engagement of the switch blade IS with the clip 39. When the switch is swung to its fully raised position, the blades l8 and I9 are both in electrical contact with the clips 38 and 39.

To facilitate the use of the control, the outer face of the casing l0 can be appropriately marked, and, thus, the casing adjacent the lower end of the slot 22 can be marked Ground, and the slot intermediate its ends can be marked Standard broadcast, while the upper end of the slot can be marked Short wave.

In use of my improved control, when it is desired to receive national or local broadcasts, the switch lever I1 is swung to a raised position until its handle 2| reaches the reading Standard broadcast on the casing, at which time the switch blade I8 will be in electrical contact with the clip 38. This will connect the lead-in wire 32 of the antenna wire section 34 with the clip 38, through the switch blade l8. The binding post 40 is connected with the binding post 44 on the radio receiving set by means of the wire 42.

When it is desired to receive short wave broadcasts, the switch lever I1 is swung to its extreme raised position and to the point indicated by the slogan Short wave. Hence, both of the switch levers l8 and I9 will be connected with the binding posts 44 and 46 of the radio receiving set.

By this arrangement the set can be quickly and conveniently connected with the desired section or sections of the aerial according to the type of broadcast being received.

When it is desired to protect the set against lightning, the switch lever I! is swung to its lowered position to the point labeled Ground." In this position, the switch lever is completely out of engagement with the clips 38 and 39, and,

thus, the radio receiving set is completely disconnected from both sections of the aerial, and these aerial sections are now connected through the binding posts 30 and 3|, switch blades I8 and I9, and clips 26 and 21 to the ground. Thus, lightning striking the aerial will be led to the ground.

In actual practice, I have found that best results can be obtained when a ground potential is used for standard broadcast reception. This ground, however, should be broken when both sections of the doublet aerial are used for receiving short wave programs. To bring about the employance of a ground for a set during standard broadcast reception, I can employ novelly arranged ground arms 50 and 5|. These arms are illustrated in Figures 5 to 7 inclusive, and the inner ends of the arms are mounted upon a common pivot pin 52, which is carried by a bracket 53. The bracket is rigidly secured to the bottom wall I2 of the casing I0 and insulated therefrom. The arm 50 is formed relatively long and is mounted between the clips 38 and 39 for free swinging movement. However, the clip 39 has formed thereon a laterally extending lug 54, against which the arm 50 normally rests. The arm 5! is considerably shorter than the arm 50 and is mounted for free swinging movement between the clips 26, and one of these clips is provided with an inwardly directed lug 55, which the arm 5| normally rests. To insure the proper electrical engagement of the arms 50 and 5| with their lugs 54 and 55, the arms 50 and 5| are connected by a contractile coil spring 56, and, hence, these springs place the arms under tension and draw the arms toward one another and toward the lugs 54 and 55. the arms 50 and 5| are located between the pairs of stationary clips, the arms are in the path of the insulating handle 20 of the switch lever I1.

This type of my control functions as follows: When the lever I1 is raised to its partially elevated position for standard broadcast reception, the switch blade I8 engages the clip 38 in the usual way, and, hence, one antenna wire section is connected with the radio set through the radio set terminal 44. The radio set terminal 46 is grounded, as the arm 50 is in electrical contact with the short clip 39, and the arm 50, in turn, is

connected by means of the arm 5! with the ground clips 26.

In short wave reception, the lever H is swung to its completely raised position, and the strip of insulation 20 will engage the lever 50 and move the same away from its lug 54 and out of electrical contact with the clip 39. Thus, the ground connection with the terminal posts 46 of the set is broken, and this terminal is electrically connected with the other side of the doublet antenna.

When the set is to be protected from lightning and the switch lever I1 is swung to its lowered position, the insulating strip 26 will engage the arm El and move the same away from its lug 55, and, thus, the arm 5| is held out of electrical contact with the ground clips 26. Consequently, the antenna is grounded, but the set is disconnected from. the ground and antenna.

Changes in details may be made without departing from the spirit or the scope of my invention, but what I claim as new is:

1. The combination with a radio receiving having a pair of independent antenna terminal posts and a doublet antenna including sections insulated one from the other; of a device for connecting one or both sections of the doublet an tenna with the terminal posts of the radio receiv ing set including, a double-bladed switch lever, means insulating one blade from the other, means including independent conductor wires electrically connecting each antenna section with a switch blade, blade contact clips, means including independent conductor wires electrically connecting the terminal posts of the radio receiving set with the blade contact clips, said contact clips being disposed in the path of the switch blades, with one of the contact clips being arranged in advance of the other, whereby the last-mentioned contact clip will be engaged by a switch blade prior to the engagement of the other contact clip by the other switch blade, clips arranged in spaced relation to the contact clips disposed in the path of the switch blades and adapted to be engaged by the switch blades when the switch is in a predetermined position and out of engagement with the contact clips, and means including a common ground terminal post and wire for grounding the last-mentioned clips.

2. An attachment for radio receiving sets comprising a casing, a pair of spaced contact clips disposed in the casing insulated one from the other and having separate binding posts for connection with separate antenna terminal posts of a radio receiving set, one of said contact clips being extended in advance of the other contact clip, a pair of ground clips in said casing electrically connected together and having a common binding post, a ground wire electrically connected to said common binding post, a doublebladed switch lever having an operating handle insulating one blade from the other, supporting brackets insulated one from the other disposed in the casing between the contact clips and the ground clips pivotally supporting and electrically connected with the switch blades, the contact clips and the ground clips being arranged in the path of the switch blades and being adapted to be engaged thereby when the switch blades are in different positions, independent binding posts electrically connected with the supporting brackets for the switch blades, lead-in wires for a doublet antenna electrically connected to the supporting brackets for the switch blades, whereby the sections of the doublet antenna can be electrically connected to the blades of the switch lever at all times, said casing having an arcuate slot therein, and the handle for the switch lever being extended beyond the casing through said arcuate slot.

3. The combination with a radio receiving set having a pair of independent antenna terminal binding posts and a ground binding post, and a doublet antenna including insulated sections, and independent lead-in wires connected to each antenna section; of a control for the radio receiving set including a casing, a doublebladed switch lever rockably mounted in the casing and insulated therefrom, a manipulating handle for the switch lever insulating one blade from the other, a binding post carried by the casing for each switch blade, the antenna lead-in wires being connected to said last-mentioned binding post, pair of spaced contact clips disposed in the casing and insulated one from the other having binding posts electrically connected therewith, conductor wires electrically connecting the 1ast-mentioned binding posts with the terminal antenna posts of the radio receiving set, one of the contact clips being arranged in advance of the other, said contact clips being mounted for engagement by the blades of the switch lever, ground clips disposed in the casing and insulated therefrom adapted to be engaged by the blades of the switch lever when the lever is in one of its positions, means grounding the ground clips and the ground binding posts of the radio receiving set, means electrically connecting one of the ground clips with one of the contact clips, and means for interrupting said last-mentioned ground connection when the switch lever is in predetermined positions.

4. The combination with a radio receiving set having a pair of independent antenna terminal binding posts and a ground binding post, and a doublet antenna including insulated sections, and independent conductor wires connected to said sections; of a control for the radio receiving set including a casing, a double-bladed switch lever rockably mounted in the casing, a manipulating handle for the switch lever insulating one blade from the other, binding posts electrically connected to the blades of the switch lever and insulated from the casing, said lead-in wires being electrically connected to said last-mentioned binding posts, a pair of spaced contact clips disposed in the casing and insulated one from the other having independent binding posts, wires electrically connecting the last-mentioned binding posts with the terminal antenna posts of the radio receiving set, one of the contact clips being arranged in advance of the other, said contact clips being mounted for engagement by the blades of the switch lever, ground clips rigidly disposed in the casing and insulated therefrom and adapted to be engaged by the blades of the switch lever when the switch lever is in one of its positions, means grounding the ground clips and the ground binding posts of the radio receiving set, means electrically connecting one of the ground clips with one of the contact clips, means for interrupting said ground connection when the switch lever is in predetermined positions, said ground means including electrically connected arms rockably mounted in the casing and normally held in electrical engagement with the mentioned clips, and said arms being disposed in the path of movement of the operating handle for the switch lever.

ROGER W. MOI-1R. 

